Multiple-Decker Sandwich Complexes of Lanthanide−1,3,5,7-Cyclooctatetraene [Ln_n(C₈H₈)_m] (Ln = Ce, Nd, Eu, Ho, and Yb); Localized Ionic Bonding Structure

Abstract

Organometallic lanthanide complexes of Ln n (C8H8) m (Ln = lanthanide metals of Ce, Nd, Eu, Ho, and Yb; C8H8 = 1,3,5,7-cyclooctatetraene) were produced by a combination of laser vaporization and molecular beam methods. The complexes having (n, m) = (n, n + 1) for n = 1−5 were prominently produced as magic numbers in the mass spectra. Using mass spectrometry, photoionization spectroscopy, and photoelectron spectroscopy, it is concluded that these magic-numbered complexes form multiple decker sandwich structures in which Ln atoms and C8H8 molecules are alternately piled up. The obtained spectroscopic data show that these sandwich complexes are formed through ionic bonds and are charge transfer complexes, where the Ln atoms are multiply charged cations of Ln k + (k = 2 and 3) and C8H8 molecules are multiply charged anions.

The bonding characteristics and electronic and magnetic properties of organometallic sandwich clusters and nanowires

“…To date, various organometallic sandwich clusters have been successfully synthesized experimentally and extensively explored theoretically. The possible metal elements include alkali (alkaline‐earth) metals, 3 d ‐transition metals (TM), 4(5) f ‐lanthanide (actinide) metals (Ln); and the organic ligand molecules can be different hydrocarbon cycles C n H n ( n = 3–8) . Particularly, in 1995, Kaya and Nakajima group have synthesized stable linearly multidecked vanadium n –benzene m (V n Bz m , Bz = benzene = C 6 H 6 ) complexes using laser vaporization technique .…”

“…One of the reasons that the metal‐ligand sandwich complexes becomes the hot research topic is their rich physical and chemical properties, which show great potential applications in catalysis, spintronics, optics, molecular recognition, biosensor, and so on. Generally, the metal atoms and ligand molecules form stable sandwich motifs via ionic‐covalent bonding and even pure ionic bonding . More interestingly, Stern–Gerlach magnetic deflection experiments have revealed linear size‐dependent magnetic moments of V n Bz n + 1 ( n = 1–4) clusters and ultrahigh magnetic moments of Eu n COT m (COT = C 8 H 8 = 1,3,5,7‐cyclooctatetraene) .…”

[(C5Me5)Yb(μ‐η8,η8‐cot′′′)Yb(μ‐η8,η8‐cot′′′)Yb(C5Me5)]—A Unique Tetradecker Sandwich Complex of a Divalent Lanthanide

“…[2,3] The first tetradecker sandwich complexes of transition metals (Fe, Co, Mn) were reported almost thirty years ago by Siebert et al [9] In contrast, linear triple-or tetradecker sandwich complexes containing two or three lanthanide centers sandwiched between polyhapto ring ligands have not yet been isolated, although there is solid evidence that the large, flat cot ligands are capable of forming such complexes with f elements. [10][11][12][13] We set out our investigation in this area by reasoning that the use of very bulky cot ligands might discourage the bending process and favor the formation of linear triple-decker sandwich structures. One of the most sterically encumbered cot ligands currently available is the 1,3,6-tris(trimethylsilyl)-cyclooctatetraenyl dianion (cot''').…”

A first principles study of novel one-dimensional organic half-metal vanadium-cyclooctatetraene wire

“…7 In addition, a great deal of attention has been paid to organometal based 1,3,5,7-cyclooctatetraene (COT). Many lanthanide complexes and transition-metal complexes (TM) sandwiched between COT rings have been successfully produced by using laser vaporization and molecular beam methods, [8][9][10][11][12][13][14][15][16] and 18 decker Eu 18 (C 8 H 8 ) 19 nanorods have been successfully synthesized in the laboratory. [17][18][19] On the other hand, the theoretical research has also been carried out.…”